The clinical features and microbiological characteristics of 315 patients with definite or possible infective endocarditis (IE) from January 1995 to December 2003 were evaluated. There were 187 males and 128 females with a mean age of 51 years (range, 1 month to 92 years). Ninety-three patients (30%) had a diagnosis of valvular heart disease and 24 (8%) had received prosthetic valve replacement. Blood culture was negative in 62 patients (20%). Staphylococci (91 patients, 32%), including methicillin-susceptible Staphylococcus aureus (15%), methicillin-resistant S. aureus (11%), and coagulase-negative staphylococci (6%), were the most commonly encountered pathogens followed by viridans group streptococci (77 patients, 24%). Eight patients (25%) had various neurological, renal, embolic, and cardiac complications. Patients with neurological complications [odds ratio (OR) 8.175, P<0.001], nosocomial IE (OR 6.661, P<0.001), underlying malignancy (OR 4.993, P<0.001), elevated serum creatinine level (OR 3.132, P=0.001), or elevated WBC count (>15000/mm3) (OR 2.537, P=0.007) were at significantly increased risk of mortality. This study found mortality from IE was associated with several factors, among which neurological complications were the most hazardous. Patients with more than one risk factor had poorer prognosis. These results suggest the need for more aggressive management in patients with IE when multiple risk factors for mortality are identified.